Jelly

Ron had heard a rumour that Malfoy was afraid of jelly.  Apparently, he was disturbed by the way it wibbled.  That was why Ron was currently sat at the back of the Potions classroom trying his damn hardest to remember a spell he had – shock horror! – researched the previous night.

His face was screwed up in fierce concentration, an expression that would have looked entirely out of place on Ron at the best of times, let alone in his least favourite lesson with the evil, menacing, annoying toe rag that was Snape lecturing the class about the advantages of Diet Pepsi in comparison to Diet Coke.

The light bulb that went ting was almost visible above the red head's right ear.  Smirking cunningly like something that's extremely cunning, Ron stood up quickly, wand raised in anticipated victory.

"Ooh, head rush…" He swayed briefly on the spot before regaining his composure and, wand pointed at the ceiling, he bellowed "Wibblius Wobblium," at the top of his voice.  Ron and his wand performed a number of complicated twirly patterns whilst he hopped on the spot and patted his right elbow with his left hand, and a sudden flash of bright pink light engulfed the entire room.

When the strawberry and cream flavoured smoke had dissipated, it became clear what Ron had done.

One platinum blond student ran for his life, girlishly high pitched screams reverberating off the old crumbly stone walls of the corridor outside the classroom, getting quieter and quieter like when Gandalf falls down the hole after waving his walking stick at the Balrog – oops, sorry, wrong franchise.

Ron had successfully transfigured all the tables into Rowntrees Strawberry Jelly.  Professor McGonagall would have been proud.